Treatment of cellulosic materials to extend their serviceable life (preservation) has many applications. Treated wood is used in fence posts, utility poles, residential and commercial decking, utility poles, railroad ties and the like.
Most methods used to treat wood are often energy and labor intensive. Presently, treatment of sapwood can require subjecting wood to a vacuum, followed by high pressure to impregnate the wood with treatment compositions. Pressures in the range of 50-250 psig can be used for preservation of wood. Typically, the use of high pressure for wood treatment requires costly pressure containment vessels, controllers and pumps. Associated maintenance costs of those pressure containment vessels and pumps can be high to assure that the pressure vessels maintain integrity (e.g. do not leak) and thus can hold pressure/vacuum. Furthermore, energy requirements of pumps for evacuation and pressurizing the pressure vessels can be high and costly. U.S. Pat. No. 3,968,276 (Allen), U.S. Pat. No. 4,399,195 (Allen) and U.S. Pat. No. 4,433,031 (Allen) disclose wood treatment compositions and methods, and are incorporated herein by reference in their entirety. Currently, most wood treatment procedures use toxic chemicals and preservatives that can have a serious impact on the environment over the lifetime of the treated wood, and during disposal of the treated wood at the end of its serviceable life. These treatment procedures may also be ill-suited to treat other cellulosic materials, such as cardboard or paperboard or mulch.
It is against this background that this disclosure is made.